Pepco Holdings Inc.'s President Joseph Rigby is going out with a bang.

Shortly after he announced his retirement in late January, Rigby was approached by Exelon Corp. President Christopher Crane about a possible acquisition. It was a signal, Rigby said Wednesday during a conference call with reporters, of confidence in the oft-maligned Pepco's work to improve reliability and customer service.

Having just put the finishing touches on the integration of Baltimore-based BGE and Constellation Energy into the Exelon portfolio, Crane said, "We thought it was a good opportunity to put another progressive operation into the Exelon family."

"We're proud of these achievements and they did not go unnoticed," Rigby said of Pepco's efforts.

"Our board came to the conclusion that Exelon was prepared to appropriately recognize our company's increasing value," he continued. "This is a tremendous opportunity to take Pepco Holdings to the next level."

With the acquisition, Exelon will become the leading energy provider in the Mid-Atlantic, with 10 million customers in southeastern Pennsylvania, the Baltimore area, D.C. and its suburbs. Exelon already owns Baltimore-based BGE and Philadelphia-based PECO. Pepco Holdings owns Atlantic City Electric, Delmarva Power and Pepco.

"We really are excited about this combination," Crane said. "It makes an enormous amount of sense."

The arrangement is expected to close in the second or third quarter of 2015, assuming that federal regulators and regulators in three states and D.C., approve the merger. To smooth that process, Exelon has announced a $100 million customer improvement fund for its territories that will be used for rate credits, energy efficiency programs and low-income assistance.

Crane said the merger will save the company roughly $80 million a year. Employees, lower level and administrative, will be affected, but it's too early to say how.

"We'll deal with that in a very fair and balanced way," Rigby said.

For D.C. and Maryland Pepco customers, the Pepco brand will remain, and Pepco will remain headquartered in the District. Its "wires only" business model will not change. Its agreement with the District to underground utilities is full speed ahead, Rigby said. And its discussions with the city to clear the way for a new D.C. United stadium at Buzzard Point will not be interrupted.